Key to Genera in the Tribe Chironomini

Ian R. Walker & K. Brodersen

Recommended Citation:
Walker, I. R., and K. Brodersen, 1997. Key to genera in the tribe Chironomini. Part I. In: I. R. Walker (Ed.), The WWW Field Guide to Fossil Midges. (http://www.paleolab.ca/wwwguide/chironomini/chir2key.htm)

Last Update: 1 June 1997

©2007 Ian R. Walker. ALL RIGHTS RESERVED

1. • a) Mentum concave (Fig. 1, 2)
     .............................................................................Key to Chironomini with a concave mentum
     
     
   • b) Mentum weakly to strongly convex (Fig. 3, 4)
     .............................................................................2.
   
   
   
   
2. • a) Outermost teeth (1 or 2 pairs) of mentum distinctly longer than adjacent teeth (Fig. 3)
     .............................................................................Key to Chironomini with enlarged outermost teeth
     
     
   • b) Outermost teeth of similar size to adjacent teeth, or smaller (Fig. 4)
     .............................................................................3.
   
   
   
   
3. • a) Anterior margin of ventromental plates broadly scalloped; mentum with light pigmentation, and 15 or 16 pointed teeth (Fig. 4).
     .............................................................................Parachironomus
     
     
   • b) Anterior margin of ventromental plates not scalloped; mentum with light or dark pigmentation, and 13 to 16 teeth (Fig. 5, 6).
     .............................................................................4.
   
   
   
   
4. • a) Mentum with an even number of teeth (Fig. 5); or if odd, then median tooth light-coloured and shorter than adjacent pair.
     .............................................................................Chironomini with an even number of teeth
     
     
   • b) Mentum with an odd number of teeth; median tooth light or dark coloured, large and conspicuous (Fig. 6).
     .............................................................................Chironomini with an odd number of teeth
   
   
   
   

Fig. 1. Stenochironomus: Left: mentum, Right: mandible

Fig. 2. Cryptochironomus.

Fig. 3. Cladopelma

Fig. 4. Parachironomus.

Fig. 5. Lauterborniella/Zavreliella.

Fig. 6. Dicrotendipes.